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stays and shrouds too loose?

7K views 15 replies 16 participants last post by  manatee 
#1 ·
Is there a general rule as to how tight a shroud or stay should be? Or is it the usual Icarus tightness measure; "not too tight, not too loose" ~LL
 
#6 ·
Doesn't it depend on your boat specs? For example, some boats require more mast rake than others to sail efficiently. I don't think the tension of the stays and shrouds on my boat would be the same as a J boat. I could be wrong but I don't think there's one overall rule of thumb that covers every sailboat.
 
#10 ·
Mast Rake is determined by forestay length, this fella is asking about rig tension.

I've been taught to crank the turnbuckle tight as you can with an open end box wrench (a small one, just 6 or 7" long) while the other hand holds the toggle. When the toggle begins to twist in your hand, that's far enough. No one should have droopy leeward stays in any wind or on any point of sail.

Having said this, rig tuning is an art, not a science.
 
#7 ·
I've heard all kinds of things.
the 'X amount' of deflection is common.
I've been told that newbies are afraid to overtighten, but shouldn't be (in other words, tighten the heck out of it...)
I've also been told that bar-tight is no good.

All of these things are subjective.

My advice? Google search 'rig tuning' for your boat, and spend some money on a Loos gauge.
I have one - it takes all the guess work out of it. I may not have the rig tuned quite right, but I know for a fact it's consistent year to year, and shroud to shroud.

(on my C&C 35, I use 1000lbs for the lowers, and 1800lbs for uppers)
 
#8 ·
#9 ·
Boatowner's Mechanical And Electrical Manual by Nigel Calder Has an excellent section on rig setup. He describes an effective way to measure the amount of stretch on the stay or shroud using simpley a tape measure and a marker of some sort. Measureing the amount of deformation under tension is a very acurate way to preload correctly.

(You will find the book helpful for other things too - I consider it a must have refference.)
 
#11 ·
The general idea is that you don't want your mast moving around a lot when you tack, and you want the mast to be evenly centered on the boat: straight up, as far as port/starboard goes. If the leeward shrouds are really loose, the mast will be swaying around in mid-tack. Not only is this slow, with the mast's weight wobbling around, but it probably puts additional cycles on the standing rigging, tending to wear it out faster. If the leeward shrouds are loose it also means the mast isn't centered. On a keel-stepped mast, this puts a side-strain at the partners, where the mast goes through the deck or cabin top. This can cause damage and leaks. Loose shrouds also mean that the mast is actually falling off to leeward on whatever tack you're on. This is really inefficient going upwind: you want the airfoil (your sail) to be as close to right angles to the wind (straight up) as possible. If your mast is falling off 10º when you're sailing the boat with the hull flat, your competition with the mast straight up will be pointing higher than you. If you heel 10º, your mast is 20º off vertical: much slower than it could be. Instead of solely working to push the boat forward, a component of the sail's lift is actually pulling the mast down towards the water, making you heel more! Keeping everything snug, even the leeward shrouds, is probably a good idea even if you're not racing.
 
#13 ·
I have about 1000 lbs. on my lower shrouds, maybe a bit more on the uppers at the dock. In 15 knots of wind, close hauled, the leeward shrouds are unloaded but not loose.
Check out the tension on other boats of similar size and rig configuration to yours and you will get a good feel for it eventually.
A Loos gauge is not very accurate and for the number of times you will use one they are way over priced for what they are.
 
#14 ·
Your sail manufacturer should be able to give you "rig tune" guidelines for your boat.
That includes recommended rake.

As for tension... some can give you Loos gauge numbers, some will give you a way to tell what tension you need.

But YES, under sail, mast otherwise in column and also straight throughout, if a leeward shroud is flopping in a moderate breeze, you are too loose.

MOST tuning guides will tell you how to "dock tune" for your coarse setting... but then tell you to sail a close hauled starboard tack, adjust the leeward shrouds to "x", then tack and do the same adjustment to the other side. Mostly because it's easier to add another crank on the shroud when its got less pressure on it.

Hadn't thought of the middle of the mast dropping if your leeward lowers were loose when you're on the wind, but it makes perfect sense. But then I could see in light air where that might be "advantageous" too. ;)

And RIG tune isn't my forte' but I've recently understood why I should get better at it!
 
#15 ·
Sailboat owners should "invest" in a Loos tension gauge, much like a vehicle owner should invest in a tire pressure gauge. The manufacturers or owners groups usually have specs available; or use a setting of 10% of breaking strength as a guideline. The only way to determine the tension setting is with a gauge of some type.
 
#16 ·
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